The accurate representation of certain materials in both manufactured form, as well as in computer generated images, is challenging. For a high quality replication that looks “real,” the appearance characteristics of the material should be accurately measured, quantified, and translated into physical characteristics (for a manufactured form) or software representations (for a computer generated image). Human skin is one such material, of many, for which an accurate replication is desired.
Processes exist for designing and fabricating real-life materials in an attempt to replicate life-like surfaces and make them appear real. For example, processes exist for developing a human-skin-like material to cover human models or animatronic items, such as robots, for use in live settings (such as amusement parks and museums). However, many existing fabrication processes and methods may ignore certain parameters of the replication material and/or target material in order to simplify the replication process. Thus, replicated materials made using these simplified processes may not appear as life-like, or sufficiently similar to, the targeted material for replication. In other instances, skilled artists may need to manually replicate these life-like materials at high cost and without the flexibility of a more automated process which relies less on the interpretation of the artist.
Computer generated images are used as content for various electronic visual media, such as movies, television, video games, software modeling, and other such items. In many instances it may be desirable to have the computer generated content accurately depict surfaces, textures, and colors. Some computer generated images model the appearance of a particular surface or material using rather simple analytical formulas that may include assumptions regarding certain subsurface light parameters. Due to these assumptions, images produced by these formulas may not sufficiently accurately match the properties of real materials to make the replication appear real.
For example, the light reflectance and color depiction of translucent materials may not be accurately represented in these earlier models because often times these formulas may ignore subsurface scattering within the material. Thus, many times replication of translucent materials may appear flat or not life-like.
It is with these shortcomings in mind that the present invention has been developed.